Fuel economizer



0. H. CUR NWELL FUEL ECONOMIZER Fil'ed June 6. 1923 3 Sheets-Sheet 5 Inven MAKM Patented Oct. 14, 1924.

UNITED STATES PATENT OFFICE.

CHARLES HORACE CORNWELL, OF I-IAlfdILTON, ONTARIO, CANADA, ASSIGNOR TO THE BURNALL CORPORATION 033 CANADA, OF HAMILTON, ONTARIO, CANADA.

FUEL ECONOMIZER.

Application filed June 6,

To all whom it may concern:

Be it known that 1, CHARLES HORACE CoRNwELL, a subject of the King of Great Britain, and a resident of the city of Hamilton, county of Wentworth, Province of Ontario Dominion of Canada, have invented certain new and useful Improvements in Fuel Economizers, of which the following is the specification.

My invention relates to improvements in fuel economizers and more particularly to the application of such devices to fire-tube boilers, and the object of the invention is primarily to improve the efliciency of these boilers by accomplishing a more complete combustion of the fuel than has hithertO been the case, thus reducing the loss due to unburnt fuel passing up the stack; a further object is to complete the combustion in such part of the boiler as will enable the heat generated to be effectively absorbed by the heating surface of the boiler, a further object is to enable these results to be obtained by the tting of a simple and inexpensive device which may be conveniently and quickly attached to any boiler; and a still further object is smoke elimination.

My invention consists essentially of a novel form of device mounted within and at the rear of the combustion chamber of a fire-tube boiler whereby heated oxygen is admitted in the form of a finely directed spray or as a number of very fine jets, into the rear of the combustion chamber adjacent to the mouth of the fire-tubes, all as hereinafter more particularly described and illustrated in the accompanying drawings in which Fig. 1 is a side elevation, partly in section, of a standard form of return tubular boiler showing my invention applied thereto.

Fig. 2 is a central vertical section of an air chamber used in my invention taken on the line 2, 2 of Fig. 3.

Fig. 3 is a section on the line 3, 3 of Fig. 2 a portion of the outer inclined wall being broken away.

Fig. 1 is a top plan view of the device. In the drawings like characters of refer- 1923. Serial No. 643,789.

ence indicate corresponding parts in the different views.

1 indicates the boiler shell of a standard return tubular boiler, 2 being the brick setting and 3 the smoke box.

4 are grate bars, 5 the ash pit, 6 the firing door, 7 the ash door and 8 the bridge.

The combustion chamber of the boiler may be divided for reference purposes into the fire box proper 9 and the rear portion located at the back of the boiler shell and adjacent to the mouths of the fire-tubes will be designated as 10.

11 is an air distributing device which comprises an enclosed hollow cast metal chamber of flat rectangular shape having its side and bottom walls inclined.

12 is an inlet pipe communicating with an inlet port 29 located centrally within the back wall of the member 11 adjacent to the upper end thereof.

The lower end of the chamber is formed with the double spaced walls 13 and 141, which walls are sloping and parallel with each other (see Fig. 2).

Each of these walls is provided with a plurality of small orifices or perforations, the orifices in the inner wall being designated by the numeral 15 and those in the outer wall by the numeral 16.

The orifices 15 and 16 are arranged in staggered relation so that the orifices in the walls 13 and 14 are not in alignment. The purpose of this will appear hereinafter.

The interior of the chamber 11 is divided into a number of communicating sections by a series of diaphragms or baffles 17, 18 and 19, the arrangement of which is shown in Fig. 3.

The baflie 17 is of arc shape and extends transversely across the device near the upper end thereof. The baffles 18 extend transversely inwardly from the two sides so that a central opening 20 is formed between the inner ends of these baffles. The baflie 19 is located centrally of the device and is in the form of an equilateral triangle with its apex directed upwardly This baliie 19 forms an orifice 21 extending through the device.

These bafties divide the device substantially into four chambers 22, 23, 24 and 25.

26 is a pipe leading upwardly from the inlet pipe 12 and 27 is a perforated rosette carried by the upper end of the pipe 26.

28 is the rear wall of the brick set of the boiler;

The construction and operation of my invention is as follows The device 11 is mounted upon the rear wall 28 ofthe boiler setting being located centrally with respect to the boiler and is so positioned that the sloping end 14 is directed downwardly and is substantially level with the bottom of the boiler shell.

The operation of my device is based upon the principle of the diffusion of gases.

VJ hen the boiler is 111 operation air is I drawn into the device through the pipe 12,

passes downwardly through the device and is discharged in the form of a finely di vided spray or a series of fine jets through the perforations in the bottom of the de Vlce; v

In order that the device may operate ethciently as will hereinafter be explained, it is essential that the air discharged from the device shall be highly heated andtherefore it is desirable that its passage through the device be rendered as slow as possible so that there will be sufficient time for the air to become heated by contact with the hot walls thereof.

For this purpose the batfies 17, 18 and 19 are provided and from an examination of Fig. 3 it will be noted that the air in passing through the device is deflected by these battles and follows substantially the devious course indicated by the arrows.

By the provision of the orifice 21 in the device the heating surface is further increased.

The path of'the gases passing from the fire box 9' is indicated by the arrows A in Fig. 1 and the airbeing discharged from the device 11 is indicated by the arrows B.

The fact is fully recognized by engineers that above the fuel bed in the fire box the gases contain a high percentage of coinbusti ble matter in the form of volatile hydrocarbon and suspended free carbon but that there is not sufiicient oxygen present for the combustion of this matter.

The air supply in sufficient quantities for the combustion of this matter cannot be obtained-by increasing the rate of air supply through the fuel bed and therefore a very large percentage of this combustible matter, which forms a considerable portion of the fuel, must pass up the stack in the unburnt condition. This results not only in considerable fuel loss and in lowered ethciency of the boiler but the suspended free carbon passes off as smoke and deposits soot in the fiues.

ing discharged at B through the device- 11 supplies the necessary amount offree oxygen for the combustion of the unburnt fuel above referred to. r V r This oxygen enters the combustion chamber in ahighly heated state and by difiusion intermingles and becomes intimately mixed with the hot gases rising from the melt d and its temperature being sufiiciently high it has no cooling action on the gases.

By my invention I so arrange the device 11 with respect to the boiler shell-that the oxygen is supplied at the point where it will mix most effectively with the gases asthey rise from the under side of the boiler shell to pass through the tubes of the boiler.

In this Way sufhcient oxygen is supplied so that the gases may be completely burnt before they pass out of the fines and rise into the smoke box 3.

It is very desirable as has been above stated that the air pass quietly out of the device 11 and with a. view of obtaining a quieter discharge 1- provide the double spaced walls 1% and 15, each of said walls being perforated but the perforations being out of alignment.

In this way the air passing through the perforations 15 in the inner wall will impinge against the outer wall 14 and thus any velocity which the air might have, retained in its passage through the devic'e'll is entirely destroyed and the air passes'quietly out through the perforations 1 6 in the outer wall 14:. I

From the foregoing it will be apparent that I have devised improvements in fuel economi'zers which will greatly improve the efliciency of boilers and suchlike. 7

Many modifications may be made inmy invention without departingfrom thespirit of the invention or the scope of the claims and therefore the exact form shown is to be taken as illustrative only and notin" alimit ing sense.

What I claim as my invention is:

A fuel economizer of the class described comprising a flat, substantially rctarrgular, enclosed chamber provided with inlet port centrally inthe back walladjacent to one end of the chamber, the opposite end wall provided with perforations, thecham ber sub-divided into a plurality of communicating sections by transversely disposed-bah. fies, said baflles consisting of an-upper'arc shaped baffle situated immediately before the inlet port and extending into proximity of the sides of the chamber, two laterally triangular bafile being removed so that a triopposed bafiles situated below the aforesaid angular opening is formed through the 10 arc-shaped baflle fang extendgng inwardly chamber.

from the sides 0 t e cham er into proximity to the centre, and a lowermost baztfie CHARLES HORACE CORNWELD' of triangular shape situated centrally of the Witnesses:

chamber, the portion of the front and back JOHN J. HAYWARD,

walls of the chamber enclosed within the NoRIEEN CoLEs. 

